True Nature
by Gabers100
Summary: Frisk has finally killed everyone but three others. Sans is the only thing in her way now. But is this what she wants? Genocide? Is this her fault? Read to find out! Working on the next part!
1. The battle begins

Sans stood in the Judgement hall, hands stuffed in his pockets and his classic grin on his face. He twirled a bone around, waiting. The scarf around his neck hung limply. The red scarf was originally from his brother, Papyrus. It was now Sans', since his brother had fallen to the Human. The human… Sans didn't know what to think of the Human. He knew of her, before… Frisk, was her name, then. Now what was she? Sans sighed openly. He knew of the Resets, but he also knew through his research of how powerful Frisk really is. She could change the world around them with the press of a button. He heard footsteps and he turned, his head, his grin still on his face. Frisk, or rather, the human, walked into the room stiffly. She went to the middle of the back and reached her hand to something Sans couldn't see, and she turned back to him. A weak smile flashed across her face, and she held the knife loosely at her Side.

"...Well, look who the Skeleton brought in." Sans said, in his always-joking style New Yorker accent. He chuckled a bit to hide his nervousness, and Frisk simply stood, looking at him blankly.

"Erm… Anyway, kid. Are you ready?" He said, and Frisk nodded stiffly. She twitched slightly, as if electrified. Her face showed fear, and Sans shifted uncomfortably. Something wasn't right. Frisk was never like this. Frisk's face went back to the blank look her eyes dulling and a dark smile crossing her lips. Sans still had the grin on his face, and he simply chuckled again to hide the bad vibes he was getting from this.

"...I'm sorr-" Sans began, and he was cut off.

"It's too late for apologies." Frisk said. Her tone was… Rather firm. Much more firm than he remembered. Was this even Frisk? Maybe it was someone else… He sighed openly, and remembered the promise he made earlier that month.

"Whelp, sorry old lady… This is why I don't make promises…." He'd say quietly. Frisk stayed silent. She looked like… She was shaking?

Frisk tried calling out for help. Something, anything. Nothing came out from her mouth. She couldn't even move. She hadn't been able to since she fell down into this cave after resetting. She'd killed everyone. EVERYONE. She had no idea how, but she had no power over herself. Each time she had encountered someone, she suddenly… Slashed, without even knowing. One second she was looking at them and the next she was standing over their ashes. The more she did it, the less power she had, until now. She was merely a puppet, for whatever was controlling her.

 _I don't know what I got into..._

She sighed internally as she looked at Sans. The skeleton simply stared back.

 _I can't go back, even if i wanted to..._

"Look who the Skeleton brought in." The skeleton said, his iconic grin never changing. It never HAD changed. It was strange, almost mask-like. Frisk simply giggled internally, and she felt a smile flashed across her lips. Did she have control again? The hand around the knife clenched and her mouth stayed shut when she tried speaking. Damn.

 _What more can I do?_

"Erm… Anyway, kid. Are you ready?" The figure across the room asked.

 _In the end it's just me and you…_

Frisk felt her head moving up and down, nodding. The hand around her knife clenched tighter. Frisk wasn't scared. She was Terrified.

 _I never wanted to play by these rules..._

She suddenly relaxed and she looked up at him. Another moment of control! She tried taking a step and suddenly felt herself turn rigid again. She almost cried aloud at that.

 _Knife in hand, I'm playing the part of the fool..._

All she needed was a second. One second to fix it.

 _So go ahead and judge me thoroughly._  
"I'm sor-" Sans began saying, and Frisks mouth moved of it's own accord, and her voice spoke without her trying.

" _It's too late for apologies."_ She said firmly, and she got into a ready stance. She began trembling in fear, and she felt her body trembling as well. She heard something from him, something about 'promises.' She stopped shaking, and ran at him, holding her knife above her head.


	2. Bones vs Steel

Sans slid to the side as the Human attempted to use an uppercut slash. He turned to her, and he snapped his fingers, causing a Gaster Blaster, one of the weapons he was able to scrounge from Alphys' lab, to appear. It fired at frisk, who leapt out of the way. He ducked under her as she slashed at him once more.

"There was an anomaly in the Space Time Continuum today… Most of the time they move back and forth, left and right…" He'd begin, launching some bone-like projectiles at her. He saw her get hit in the leg, and a hint of pain flashed across her face. Sans shifted as she stumbled, then regained her footing and ran at him again. He pulled up a wall of bones to block her, and she smashed through them, her face and hands showing small cuts. A tear or two was showing on her face. She slashed again, trying to hit him once more. He dodged to the side and looked at her, and she looked up.

"You're not very strong, are you, Sans?" She said, in a voice that seemed like it was overlapping her original voice. He shifted his weight.

"Throwing one attack after the other…" She continued, twirling her knife around like it was a toy. Something in her eyes looked malicious. Evil. Monstrous.

"You won't bring back your poor brother." She said, a large grin coming across her face. Sans stared at her, his own grin still there. A single tear welled in an eye, and he sighed shakily, before launching more bone projectiles at her.

Frisk cried out inside her head as she burst through the wall of bones, the pain nearly unbearable. She slashed at Sans. No! She wouldn't kill another person, especially not Sans. She felt tears on her face as she hacked at him, and he moved to the side. She looked up at him, and her mouth and vocal cords began moving again, of their own accord.

"You're not very strong, are you, Sans?" She said. No, he is very strong. The strongest of them all.

"Throwing one attack after the other…" She continued, twirling her knife around like it was a toy. How was she doing that? She didn't try, but it was like she was simply a subconscious thought.

"You won't bring back your poor brother." She said, a large grin coming across her face, while inside she began crying. No! She didn't mean that! Sans sighed shakily, and a single tear was in one of his eyes. Frisk wanted to just collapse, to stop this here and now. Sans fired more bone projectiles and she ran at him again, ducking under them. She began a slash, and Frisk was able to move it to the side, causing it to miss him. Sans looked into her eyes for a second as Frisk began shaking, a fight erupting between Her and whoever was controlling her. Sans slid back as The Other regained control and attempted a stab. Frisk cried out once more when one of Sans' strange Laser Weapons hit her in the shoulder, causing her to hit the ground. She sat up quickly, diving to the side as bones hit the ground infront of her. Was Sans holding back too? She stood up and rushed at him again, taking a bone in the arm in the process.

"Back and forth, left and right... Until all the timelines ended." He said simply, dodging another attack. Frisk didn't want this. She never wanted this.

"That's your fault isn't it?" He said, his eyes turning pitch black and his voice becoming a deadpan. Frisk paused for a second, and Frisk tried grappling for control of her body again, and she shifted. The hand around her knife struggled to keep it held in her hand.

 ** _Two down now. What do you think? Review, Like, subscr-er, favorite, etc._**

 ** _-Architech, who dunked Sans like a cookie in milk._**


	3. Evil versus Determination

Sans noted the knife in her hand wavering, and he tried taking out Frisk's legs. She jumped above the Gaster blaster shots and ran at him again, her eyes back to their dull red. She slashed at his chest, and he backed up, firing a Gaster, which missed. He fired another, and another. Each missed.

"If I could only hit you once, it would be over!" Frisk proclaimed, ducking under the last gaster and trying to thrust her knife into Sans.

Frisk ducked, rolled, and weaved through the laser blasts.

" _If I could only hit you once it would be over!"_ She heard herself say, and a tear formed, falling down her cheek.

 _But the consequences would last forever!_

She'd try and thrust her knife into Sans' chest, and he'd take a few more steps back, turning so he was facing Frisk's side. He launched another bone, and it barely missed her cheek. The bone cut her cheek slightly. Not enough to make her bleed, but it still stung. She slashed again, and Sans ducked to the side again. They were facing each other.

"...Anyway, kid. Uh… I know you're really liking, uh… Swinging that thing around." He'd say, and internally frisk was once again fighting that Other. She started trembling slightly as the two minds tried dominating eachother.

"...Listen." He'd look down, then back up at frisk.

"i know you didn't answer me before, but... somewhere in there. i can feel it."

Frisk's hands trembled for a second, then her hand tightened around her knife.

"there's a glimmer of a good person inside of you. the memory of someone who once wanted to do the right thing." He continued, and Frisk again began shifting, her Other beginning to... Lose control. A voice came through her head, seeming to only heard by her.

"Who said you were the one in control here?" A voice said, taunting her.

 **Third down. Thanks for the reviews guys! We're almost there, so Stay DETERMINED!**

 **-Architech,**


	4. The Reset

"someone who, in another time, might have even been... a friend?" He said, and A single tear fell from Frisk's face, impacting the ground. "C'mon, buddy. do you remember me?" Sans asked. Frisk's hand trembled and nearly dropped the knife. Frisk kept pushing against the Other. She was almost there! "please, if you're listening... let's forget all of this, ok? just lay down your weapon, and... well, my job will be a lot easier." Sans said, standing there. Frisk collapsed to her knees, sobbing. She had finally broke free. She had won. Sans simply watched, his grin still on his face. He sighed, his face unmoving. "Sorry about that, kid…" He'd say softly, as Frisk continued sobbing. After a few minutes they began dwindling, and she looked up at Sans, with her tear-streaked eyes.  
"Th...Thank you…" She'd say quietly. Her tone was softer, and Sans nodded.

"Any time, kiddo." He'd ruffle her hair slightly, and she'd smile a bit, wiping her tears away.  
"I… I Didn't mean to… Cause this, Sans…" She'd say, her voice almost a whisper.

"I know, kid…" Sans said, kneeling down to Frisk's level. "Don't worry, we can fix it." She'd nod silently, standing up.

"...I'll see you in Snowdin." She said, smiling, and Sans nodded. "Don't forget to shake my hand, kid." He'd say, before she looked at the menu, and pressed RESET. The world went white, just like the previous four times.

…. _Undertale._

 **There you have it everyone, That's True Nature's first 'chapter.'**

 **I'll be sure to add more soon, so follow if you enjoyed! Review if you liked it, etc.**

 **-Architech, Angel Of The Underground**


	5. Update 1

**Heya everyone, Architech here. I'm having a bit of difficulty on working my next few chapters, so stay Determined and check every once in a while! I'm giving you all a little preview on the next chapter, so go ahead and read on!**

Frisk bolted awake, looking around. She was laying a flower bed, back in the beginning. It was like a movie her mom made her watch her when she was younger, called 'Groundhog Day'. It was about a man who, every time he fell asleep at night, woke up to the same day. She fell asleep halfway through, so she didn't remember the end. She stood up and walked towards the door, where a certain familiar flower was waiting.

"Howdy!" The flower said, it's… face, showing a cheery smile.

"I'm flowey! Flowey the-"

"Flower." Frisk said, in a tired tone.

Flowey looked up at her, a smile still on his face. "We've met before, haven't we?"

"Yep."

"Good. Then you know how it is in this world, right?"

"Uh-huh." Frisk said, simply walking by. Flowey frowned.

"Hey! Don't just walk off on me!" The flower said, in an annoyed tone.

"Yeah, whatever." Frisk said, continuing.

"Get back here!" Flower said, anger flaring up in his voice. A bullet passed Frisk's head, and she'd turn.

"Listen, flowey, I know you want to give me the game again, but I just want to see a friend." Frisk said, and Flowey simply smiled.

"Whatever you say, but just remember…. I'm always watching you!" He'd say cheerily and he'd go into the ground, disappearing.

Frisk shivered slightly. She _really_ hated that flower.


	6. Bonus Chapter 1!

Sans waited in the Judgement hall, smiling his usual smile. A few tear-streaks were shown on his face. He knew what happened. Frisk wasn't there anymore, was she? She was replaced by this… Thing. He sighed. Soon he heard footsteps. He looked up from the floor and found… Whoever Frisk had become. He had heard rumours, but… He didn't know her name… Did he? His head had been hurting recently, and he knew why. The timelines were fading. He was the last defense against… The end. All of it. The world, the memories… The resets. He sighed, before grinning. "Well kid, you made it. Here we are, finally…"

The child simply smiled in a sinister way as they held their knife at their side.

 _Things are getting kinda dark here._

He'd simply pull the hood off his head, and he'd put his hands in his pockets.

"You ready?" He asked, and the Human nodded.

 _But i was told to never ever fear._

Sans blinked, and his left eye glowed a bright, neon-like blue. His other eye was… pitch black. He'd pull up his hand, and bones would materialize out of the air. He thought he heard something… Or someone, say his name… Was that who he thought it was?

 _What are these whispers in my ear?_

He'd thrust his hand towards the human, and she'd get shoved towards the wall.

 _Why do i feel like i'll disappear?_

The human grunted as they impacted the wall, and Sans sighed inwardly. "Sorry kid…"

 _Suddenly i have the urge to fight._

Sans launched the bones towards the Human, who rolled to the side, causing the bone projectiles to miss.

 _Knowing the lines are fading from sight,_

The human ran forward and Sans snapped his fingers, causing a Gaster Blaster, a weapon he scrounged from Alphys' hidden lab, to appear. It fired a laser-like beam at the Human, who slid under the blast and went back up. She slashed at him, and he began backing up, dodging every slash.

 _I must stop the human from reaching light._

The skeleton grinned as he disappeared and reappeared behind the Human, firing a bone which hit the Human's leg. She grunted and turned, running at him again.

 _I will not lose this fight._

Sans dodged another attack, and fired a Gaster Blaster at the Human, who jumped over the laser-like attacks and hacked at him again. Sans ducked under it, and the Skeleton hit her, head on, with a Gaster Blaster. The human yelled in anger as her LV dropped low, but she survived the blast. Sans grunted.

"Pretty DETERMINED, aren't ya?" Sans said, winking slightly. The human sat down, eating a sandwich. Sans sighed, waiting for her to finish. As soon as she finished eating, she stood up. The cuts and bruises and burns on her faded. Sans simply grinned again. "Whatever, kid. You'll run outta items eventually."

The human simply smiled a sinister smile and rushed at him once again. Only one of them would walk away from this.

 **There you have it, that's the extra bonus to 'true nature!' I'll be sure to work on the next part of the actual story soon!**

 **-Architech, the last Spaghettibender**


End file.
